tests/test-dispatch.t

rhg: Port Python’s `ui.configlist` as `Config::get_list`

This new method is not used yet outside of its own unit tests,
so this changeset should make no observable change.

The Rust parser implementation attempts to exactly replicate the behavior of
the Python one, even in edge cases where that behavior is… surprising.
New unit tests capture some of these edge cases.

This started as a line-by-line port. The main changes are:

* Pass around a parser mode enum instead of parser functions
* Inline the whole parser into one function
* Use `[u8]::get` which returns an `Option`,
  instead of indexing  after explicitly checking the length.

Differential Revision: https://phab.mercurial-scm.org/D11389

test command parsing and dispatch

  $ hg init a
  $ cd a

Redundant options used to crash (issue436):
  $ hg -v log -v
  $ hg -v log -v x

  $ echo a > a
  $ hg ci -Ama
  adding a

Missing arg:

  $ hg cat
  hg cat: invalid arguments
  hg cat [OPTION]... FILE...
  
  output the current or given revision of files
  
  options ([+] can be repeated):
  
   -o --output FORMAT       print output to file with formatted name
   -r --rev REV             print the given revision
      --decode              apply any matching decode filter
   -I --include PATTERN [+] include names matching the given patterns
   -X --exclude PATTERN [+] exclude names matching the given patterns
   -T --template TEMPLATE   display with template
  
  (use 'hg cat -h' to show more help)
  [10]

Missing parameter for early option:

  $ hg log -R 2>&1 | grep 'hg log'
  hg log: option -R requires argument
  hg log [OPTION]... [FILE]
  (use 'hg log -h' to show more help)

"--" may be an option value:

  $ hg -R -- log
  abort: repository -- not found
  [255]
  $ hg log -R --
  abort: repository -- not found
  [255]
  $ hg log -T --
  -- (no-eol)
  $ hg log -T -- -k nomatch

Parsing of early options should stop at "--":

  $ hg cat -- --config=hooks.pre-cat=false
  --config=hooks.pre-cat=false: no such file in rev cb9a9f314b8b
  [1]
  $ hg cat -- --debugger
  --debugger: no such file in rev cb9a9f314b8b
  [1]

Unparsable form of early options:

  $ hg cat --debugg
  abort: option --debugger may not be abbreviated
  [10]

Parsing failure of early options should be detected before executing the
command:

  $ hg log -b '--config=hooks.pre-log=false' default
  abort: option --config may not be abbreviated
  [10]
  $ hg log -b -R. default
  abort: option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo
  [10]
  $ hg log --cwd .. -b --cwd=. default
  abort: option --cwd may not be abbreviated
  [10]

However, we can't prevent it from loading extensions and configs:

  $ cat <<EOF > bad.py
  > raise Exception('bad')
  > EOF
  $ hg log -b '--config=extensions.bad=bad.py' default
  *** failed to import extension bad from bad.py: bad
  abort: option --config may not be abbreviated
  [10]

  $ mkdir -p badrepo/.hg
  $ echo 'invalid-syntax' > badrepo/.hg/hgrc
  $ hg log -b -Rbadrepo default
  config error at badrepo/.hg/hgrc:1: invalid-syntax
  [30]

  $ hg log -b --cwd=inexistent default
  abort: $ENOENT$: 'inexistent'
  [255]

  $ hg log -b '--config=ui.traceback=yes' 2>&1 | grep '^Traceback'
  Traceback (most recent call last):
  $ hg log -b '--config=profiling.enabled=yes' 2>&1 | grep -i sample
  Sample count: .*|No samples recorded\. (re)

Early options can't be specified in [aliases] and [defaults] because they are
applied before the command name is resolved:

  $ hg log -b '--config=alias.log=log --config=hooks.pre-log=false'
  hg log: option -b not recognized
  error in definition for alias 'log': --config may only be given on the command
  line
  [10]

  $ hg log -b '--config=defaults.log=--config=hooks.pre-log=false'
  abort: option --config may not be abbreviated
  [10]

Shell aliases bypass any command parsing rules but for the early one:

  $ hg log -b '--config=alias.log=!echo howdy'
  howdy

Early options must come first if HGPLAIN=+strictflags is specified:
(BUG: chg cherry-picks early options to pass them as a server command)

#if no-chg
  $ HGPLAIN=+strictflags hg log -b --config='hooks.pre-log=false' default
  abort: unknown revision '--config=hooks.pre-log=false'
  [255]
  $ HGPLAIN=+strictflags hg log -b -R. default
  abort: unknown revision '-R.'
  [255]
  $ HGPLAIN=+strictflags hg log -b --cwd=. default
  abort: unknown revision '--cwd=.'
  [255]
#endif
  $ HGPLAIN=+strictflags hg log -b --debugger default
  abort: unknown revision '--debugger'
  [255]
  $ HGPLAIN=+strictflags hg log -b --config='alias.log=!echo pwned' default
  abort: unknown revision '--config=alias.log=!echo pwned'
  [255]

  $ HGPLAIN=+strictflags hg log --config='hooks.pre-log=false' -b default
  abort: option --config may not be abbreviated
  [10]
  $ HGPLAIN=+strictflags hg log -q --cwd=.. -b default
  abort: option --cwd may not be abbreviated
  [10]
  $ HGPLAIN=+strictflags hg log -q -R . -b default
  abort: option -R has to be separated from other options (e.g. not -qR) and --repository may only be abbreviated as --repo
  [10]

  $ HGPLAIN=+strictflags hg --config='hooks.pre-log=false' log -b default
  abort: pre-log hook exited with status 1
  [40]
  $ HGPLAIN=+strictflags hg --cwd .. -q -Ra log -b default
  0:cb9a9f314b8b
  $ HGPLAIN=+strictflags hg --cwd .. -q --repository a log -b default
  0:cb9a9f314b8b
  $ HGPLAIN=+strictflags hg --cwd .. -q --repo a log -b default
  0:cb9a9f314b8b

For compatibility reasons, HGPLAIN=+strictflags is not enabled by plain HGPLAIN:

  $ HGPLAIN= hg log --config='hooks.pre-log=false' -b default
  abort: pre-log hook exited with status 1
  [40]
  $ HGPLAINEXCEPT= hg log --cwd .. -q -Ra -b default
  0:cb9a9f314b8b

[defaults]

  $ hg cat a
  a
  $ cat >> $HGRCPATH <<EOF
  > [defaults]
  > cat = -r null
  > EOF
  $ hg cat a
  a: no such file in rev 000000000000
  [1]

  $ cd "$TESTTMP"

OSError "No such file or directory" / "The system cannot find the path
specified" should include filename even when it is empty

  $ hg -R a archive ''
  abort: $ENOENT$: '' (no-windows !)
  abort: $ENOTDIR$: '' (windows !)
  [255]

#if no-outer-repo

No repo:

  $ hg cat
  abort: no repository found in '$TESTTMP' (.hg not found)
  [10]

#endif

#if rmcwd

Current directory removed:

  $ mkdir $TESTTMP/repo1
  $ cd $TESTTMP/repo1
  $ rm -rf $TESTTMP/repo1

The output could be one of the following and something else:
 chg: abort: failed to getcwd (errno = *) (glob)
 abort: error getting current working directory: * (glob)
 sh: 0: getcwd() failed: $ENOENT$
Since the exact behavior depends on the shell, only check it returns non-zero.
  $ HGDEMANDIMPORT=disable hg version -q 2>/dev/null || false
  [1]

#endif